( 16 ) 



inches in length, and the segments from half a line to half an inch, or 

 nearly an inch, in breadth ; axils mostly rounded, and apices obtuse or 

 truncate, divisions more or less regularly dichotomous, sometimes 

 palmate upwards, mostly veiy shoi't and linear or obcuneate, the margin 

 entire or slightly fringed with subfoliaceous cilise. Stiaictm'e uniformly 

 cellulai', central cells rather small, roundish angular, those at the svirface 

 very minute. Tubercles subspherical, sessile, mostly placed along and 

 just within the margin of the segments, apparently common, occasionally 

 a few on the disc. Tetraspores apparently less common, forming cloud- 

 like spots in the upper segments of the frond, oblong ovate, divided 

 transversely into foiu: segments, or sporules. Substance membranous, 

 but rather firm and not adhering to paper in drying. Colour, a bright 

 rosy red when fresh, but in some varieties becoming brownish when dry. 



An extremely variable plant, in almost all its characters. 



Mr. Moore has veiy kindly supplied us with specimens of both 

 /3 and y, both abundantly fm-nished with tubercles. In variety y, the 

 segments are broad and considerably expanded upwards, much con- 

 tracted in drying, and the colour has changed to a brownish orange. 

 The margin is copiously furnished with simple or repeatedly divided 

 leaflets. In variety /3, the frond is much narrower, less divided ; the 

 upper segments mostly tapering to a point, and the margin more or less 

 fringed with minute, setaceous, or somewhat leaf-like cilise, abundantly 

 dotted with tubercles, especially in the less ciliated varieties, aU round 

 the margin of the segments. 



Like many other species, this appears to be an ocean weed, and has 

 not, so far as we know, been found growing on the east coast, being 

 mostly confined to the south of England, and south and west of Scotland 

 and Ireland. 



EXPLANATION OF PLATE LXXI. 



Fig. 1. — Rhodophyllis bifida, natural size. 

 2. — Segment with tubercles. 

 3. — Vertical section of a tubercle. 

 4. — Spores from same. 

 5. — Segment witb tetraspores. 

 6. — Tetraspores. All magnified. 



